Behaviour and design of stainless steel-concrete composite beams

Stainless steel-concrete composite beam has been regarded as a new application that is widely applied in offshore bridges and high-rise buildings and is attracting increasing interest from engineering community. The benefits brought by stainless steel, such as superior corrosion and fire resistance, high strength and ductility as well as improved durability, could offer optimal and sustainable solutions for infrastructures and highways. However, the current design provisions for composite beams are based on the assumption of an elastic-perfectly-plastic steel model which is different to stainless steel material with a rounded stress-strain curve and significant strain hardening. To develop rational design guidance, this paper carried out a comprehensive experimental, numerical and analytical study on the behaviour of stainless steel-concrete composite beams. A series of tests were conducted on eighteen full-scale stainless steel composite beams under bending, shear as well as combined bending and shear. Three dimensional finite element (FE) model was developed in ABAQUS and FE simulations were carried out to complement the experimental program. New analytical models were proposed for predicting the moment capacity of stainless steel-concrete composite beam. Additionally, a modified design approach for shear capacity was recommended based on the design guidance in AS/NZS 2327. The applicability of current moment-shear interaction defined in AS/NZS 2327 and EN 1994-1-1 was assessed by the obtained results.